<template>
  <div class="todo-footer" v-show="total">
    <label>
      <input type="checkbox" :checked="isAll" @change="cheakAll" ref="checkbox"/>
    </label>
    <span>
          <span>{{doneTotal}}</span> / {{total}}
        </span>
    <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "MyFooter",
  props:['todos','checkAllTodo',"clearAllTodo"],
  computed:{
    total(){
      return this.todos.length
    },
    //计算勾选数量
    doneTotal(){
      let i=0;
      this.todos.forEach(todo=>{
        if (todo.done){
          i++;
        }
      })
      return i;
    },
    isAll(){
      if (this.total===this.doneTotal&&this.total>0){
        return true;
      }else {
        return false;
      }
    }
  },
  methods:{
    cheakAll(){
      this.checkAllTodo(this.$refs.checkbox.checked)
    },
    clearAll(){
      this.clearAllTodo();
    }
  }
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}

</style>
